﻿#region Copyright & License

//
// Author: Ian Davis <ian.f.davis@gmail.com> Copyright (c) 2007-2008, Ian Davs
//
// Portions of this software were developed for NUnit. See NOTICE.txt for more
// information. 
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.
//

#endregion

#region Using Directives

using System;
using Ensurance.Constraints.Binary;
using Ensurance.Properties;

#endregion

namespace Ensurance.Constraints.Binary
{
    /// <summary>
    /// AndConstraint succeeds only if both members succeed.
    /// </summary>
    public class AndConstraint<T> : BinaryConstraint<T>
    {
        /// <summary>
        /// Create an AndConstraint from two other constraints
        /// </summary>
        /// <param name="left">The first constraint</param>
        /// <param name="right">The second constraint</param>
        public AndConstraint( Constraint<T> left, Constraint<T> right )
            : base( left, right )
        {
        }

        /// <summary>
        /// Apply both member constraints to an actual value, succeeding
        /// succeeding only if both of them succeed.
        /// </summary>
        /// <param name="actual">The actual value</param>
        /// <returns>True if the constraints both succeeded</returns>
        public override bool IsSatisfiedBy( T actual )
        {
            Actual = actual;
            return Left.IsSatisfiedBy( actual ) && Right.IsSatisfiedBy( actual );
        }

        /// <summary>
        /// Write a description for this contraint to a MessageWriter
        /// </summary>
        /// <param name="writer">The MessageWriter to receive the description</param>
        /// <exception cref="ArgumentNullException">if the message writer is null.</exception>
        public override void WriteDescriptionTo( IMessageWriter writer )
        {
            if ( writer == null )
            {
                throw new ArgumentNullException( "writer" );
            }
            Left.WriteDescriptionTo( writer );
            writer.WriteConnector( Resources.And );
            Right.WriteDescriptionTo( writer );
        }
    }
}